Electric razor with adjustable cutter



Dec. 3, 1968 K. MOSER ETAL 3,413,719

ELECTRIC RAZOR WITH ADJUSTABLE CUTTER Filed May 26. 1966 3 Sheets-Sheet 1 JLQQ Y MM ATTORNEY 1968 K. MOSER ETAL 3,

ELECTRIC RAZOR WITH ADJUSTABLE CUTTER Filed May 26, 1966 5 Sheets-Sheet 2 INVENTORS ATTORNEY 1968 K. MOSER ETAL 3, 13,719

ELECTRIC RAZOR WITH ADJUSTABLE CUTTER Filed May 26. 1966 5 Sheets-Sheet 5 INVENTORS ATTORNEY nited States Patent 0 ice ELECTRIC RAZOR WITH ADJUSTABLE CUTTER Kuno Moser, Unterkirnach, Germany, and Kurt Biiuerle,

Schramberg-Sulgen, Germany Filed May 26, 1966, Ser. No. 553,084 Claims priority, application Germany, May 31, 1965, M 65,405 9 Claims. (Cl. 30--43.2)

ABSTRACT OF THE DISCLOSURE An electric razor having a cutting plate provided with a plurality of cylindrical bores. A circular cutting blade is positioned within each bore and is of a diameter smaller than said bore. Drive means interconnected to the cutting blades move same eccentrically within the bores so that the cutting blade slides around the bore for performing a cutting function. The cutting plate is adjustable relative to the cutting blades to permit adjustment of the closeness of shave obtainable by razor. Guide means are provided for controlling the eccentric motion of the cutter blades.

The invention relates to razor heads for electric razors.

Most of the razors used at the present time operate on the shearing principle. In order to protect the facial skin against injury and for conveyance of the beard-hair, a shearing comb is provided above the cutting plate and above electrically driven oscillating razor blades which are provided in the manner of a comb. In order to obtain the minimum distance between the razor blades and the skin, so that the beard-hair may be cut off as closely to the skin as possible, the shearing comb is generally provided in the form of a thin, sieve-like perforated or slotted foil.

In other known electric razors, the shearing comb and the perforated or slotted foil are omitted, and the cutting plate and cutting blades are so positioned that their cutting edges face each other in the surface of the razor head. In apparatus of this kind, the beard-hair is nipped off directly on the skin of the face instead of being shorn 01f.

In an electric razor of an alternative construction, which is based on the same cutting principle, the cutting plate is provided with numerous small circular recesses or clearances having ground cutting edges, in the interior of which recesses circular cutting blades are moved eccentrically so that their cutting edges slide along the cutting edges of the recesses provided in the surface of the razor head. In this construction, the cutting edges are formed by the outwardly bevelled heads of cutting bolts which are secured in position in an eccentrically moving cutting-bolt plate. Electric razors of this kind enable a particularly close shave to be secured.

The sensitivity of the skin is, however, not the same for everybody, and, moreover, varies at different position of the facial skin and of the skin of the neck. Furthermore, the thickness and density of the beard-hair vary substantially with different people so that electric razors of the aforementioned kind, which are intended for a close shave, are not always suitable. Finally, razors of this kind have the disadvantage that the sharp cutting edges of the recesses provided in the cutting plate and the sharp cutting edges of the cutting bolts are quickly worn and become blunt owing to their rubbing against each other.

It is an object of the invention to remove these disadvantages.

According to the invention, the circular recesses in the cutting plate are provided in the form of cylindrical bores,

3,413,719 Patented Dec. 3, 1968 and the relative levels of the cutting plate and of the cutting-bolt plate may be adjusted.

It should be noted that with appropriate modification of the characteristic features hereinbefore described, the invention may also be applied to electric razors in which the relative movements between the cutting-bolt plate and the cutting plate, which movements are required for the cutting operations, are produced by eccentric movements of the cutting plate.

Further features of the invention are hereinafter described with reference to a few constructions diagrammatically illustrated by way of example in the accompanying drawings, in which:

FIGURE 1 shows a partial cross-section of a first construction according to the invention with the cutting bolts in the position for a close shave;

FIGURE 2 shows a similar partial cross-section with the cutting bolts in the position for preliminary shaving;

FIGURE 3 shows a part-sectional side elevation of the razor head illustrated in FIGURES 1 and 2;

FIGURE 4 is a perspective view of the adjusting device in the position for a close shave;

FIGURE 5 shows a corresponding representation with the adjusting device in the position for a preliminary shave;

FIGURE 6 shows a partial cross-section of a second construction according to the invention, and

FIGURE 7 shows a partial cross-section of a third constniction according to the invention.

The razor, part of which is shown in FIGURES 1 to 3, has an a blong, =0val, or round top housing part 1 into which extends the drive in the form of a hub 4 of a gear Wheel 5 which may be driven, for example by an electric motor, and which is rotatable by means of ball bearings 2 on a shaft 3. A lateral bowspring 6 acting radially in the direction of the shaft is secured to the hub 4 and to the gear wheel 5 respectively.

The top part 1 is closed by a cutting plate 7, which is provided with numerous cylindrical bores 8. Extending into the bores 8 are the heads of cutting bolts 10, which bolts are secured to a support means in the form of cutting-bolt plate 11. The heads of the cutting bolts form outwardly bevelled cutting edges 9. At its centre the plate 11 is secured to a downwardly extending flange bolt 12 part of which extends into the cavity 61 of the hub 4. Secured to the flange 'bolt 12 is a rotatable ring 13 which, sliding on an oil-impregnated ring 14 secured in position in the top part of the hub 4, bears against the bow-spring 6, which causes the cutting-bolt plate 11 to carry out eccentric movements during the rotational movements of the drive 4, 5 as explained hereinafter. The diameter of the bores 8 exceeds the diameter of the cutting edges 9 by twice the extent a of the "eccentricity of the movements of the plate, so that the cutting edges 9 guided eccentrically to a corresponding extentawithin the bores 8, slide along the inner surfaces of the bores 8. In doing so, they cut or nip off the beard-hair disposed between themselves and the inner faces of the bores 8.

The cutting plate 7 is provided with guide means which comprise two or more additional bores 63 which correspond exactly to the bores 8, and into which extend relief rollers 64 the diameter of which corresponds to that of the cutting edges 9. The rotatable rollers 64 which are secured in position at the desired level by means of straps 15 secured to the plate 11, are mounted on flange bolts 16 which are screwed to the plate 11 by means of threaded bushings 17. The relief rollers 64 mounted on the plate 11 are thus held in engagement with the sidewalls of the bores 63 by means of the bow spring 6 which bears against the ring 13 secured to the flange bolt 12, thereby biasing the flange bolt 12 and the support plate 11 secured thereto in a direction substantially transverse to the rotational axis of the hub 4. The biasing force of the spring 6 thus causes the plate 11 to be positioned eccentrically with respect to the shaft 3 with the eccentric movement being limited by means of the relief roller 64 contacting the sidewalls of the bore 63. In this manner, the eccentric movement of the support plate 11 and the cutting bolts 10 thereon is accurately controlled, the cutting bolts 10 and their cutting edges 9 being moved in the desired eccentric manner with the cutting edges being positioned substantially in contact with the upper ends of the respective bores 8 for performing a cutting function. However, the majority of the transverse force imposed on the support plate 11 by the drive means is transferred to the plate 7 by means of the relief rollers 64 and thus this relieves the high contact pressure which would otherwise exist on the cutting edges 9 whereby the cutting edges remain sharp for long periods of time.

Mounted in the bushings 17 passing through the bores 18 provided in the top part 1 of the housing, are cap screws 19 which are screwed upwardly into the bushings 17, the screws 19 together with intermediate sleeves 20 securing a spring plate 21 to the plate 11. At positions diametrically opposite the bores 18, the top part 1 of the housing is provided with equal numbers of blind bores 22 and upwardly and downwardly widened thereaded 25 which in turn causes the balls 26 to be moved vertically upwardly causing the support plate 11 to be moved vertically relative to the housing 1. This upward movement of the support plate 11 causes a corresponding deflection of the rim or peripheral portion of the spring plate 21 due to the interconnection of the spring plate 21 to the support plate 11 by means of the bolts 16 and screws 19. The support plate 11 is maintained in the newly adjusted position by means of a contact which exists 'between the spring late 21 and the balls 24 confined within the blind bores 22. However, since the balls 24 are located radially inwardly of the screw pins 25, the peripheral portion of the spring plate 21 can deflect so as to permit small amounts of vertical adjustment to occur. In this manner, the position of the cutting edges 9 with respect to the cutting plate 7 can be accurately adjusted.

Considering the operation of the device as illustrated in FIGURE 1, the drive gear 5 is rotated by a drive means, not shown, which in turn causes rotation of the hub 4 supported by the bearings 2 on the stationary shaft 3. Rotation of the drive gear 5 also causes a rotation of the bow spring 6 since the lower ends of the bow spring is secured to the drive gear 5. However, since the bow spring 6 bears against the ring 13 and causes a lateral displacement of the support plate 11, which lateral displacement is limited by engagement between the relief roller 64 and the sidewalls of the bore 63, rotation of the bow spring 6 thus causes an orbital or eccentric displacement of the ring 13 and of the support plate 11 secured thereto. The orbital or eccentric movement of the support plate 11 is of a circular nature due to the rolling engagement of the relief roller 64 with the sidewalls of the bores 63. Thus, the support plate 11 undergoes one circular orbit for each corresponding revolution of the 'bow spring 6 secured to the gear 5. The cutting bolts 10 secured to the support plate 11 thus also undergo a corresponding eccentric movement whereby the cutting edges 9 thus substantially slide around the complete circumference of the bores 8 to perform a cutting function.

The cutting plate 7 rests on an adjusting ring 27 which is mounted on the top edge of the top part 1 of the housing so as to be rotatable to a limited extent. Clearances 28 provided in the adjusting ring 27 enclose fitting or adjusting pins 30 which, being inserted in the top part of the housing 1, extend into dummy holes 29 provided in the cutting plate 7, the ring 27 having a plurality of rectangular, downwardly directed projections in the form of depressions or offset portions 31 with inclined sliding surfaces 32.

The top edge of the top part 1 of the housing is provided with cavities 33 corres oding to the depressions 31. 32 provided in the adjusting ring 27. The cutting late 7 is pressed by fixed, bent springs 34 of U-section against the adjusting ring 27, the springs 34 being secured to the cutting plate 7 and to the inside wall of the upper part 1 of the housing.

When the adjusting ring 27 is in the position illustrated in FIGURE 4, its depressions 31 are disposed in the cavities 33 provided in the top part 1 of the housing. The cutting plate 7 is in its lowermost position, illustrated in FIGURE 1, in which the cutting edges 9 of the cutting bolts 10 are in alignment with the surface 35 of the razor head. The beard hair is thus cut off by the cutting edges 9 directly on the skin with resultant very close shave.

When the adjusting ring 27 is turned in the direction indicated by the arrow A in FIGURE 5, until the depressions 31 of the adjusting ring 27 slide along the sliding surfaces 32 and out of the cavities 33 provided in the top part 1 of the housing, the cutting plate is raised to the extent b which may, for example, amount to about 0.1 mm. The cutting edges 9 are then disposed below the surface 35 of the razor head to the extent b, as illustrated in FIGURE 2, so that a less close shave, or a preliminary shave is obtained.

As far as the above-described vertical adjustment is concerned, the constructions illustrated in FIGURES 6 and 7 also incorporate therein vertical adjustment means of the same type as described above relative to FIGURES l to 5. However, the embodiments illustrated in FIGURES 6 and 7 utilize different drive mechanisms therein and further utilize different means for relieving the cutting edges substantially as hereinafter described.

As illustrated in FIGURE 6, the central part of the housing contains two rotatable gear wheels 42 which, being mounted on two continuous, rigid shafts 41 extending into the cutting plate 7, are driven simultaneously in the same direction of rotation by a pinion 43 which is mounted on a motor shaft, not shown in the drawing. The two gear wheels 42 have upwardly directed hubs 44 into each of which are pressed two bearing bushings 45, 46. At positions above the upper bearing bushings 46, a lubricating felt ring 47 and a further bearing bushing 48 are inserted in each hub 44, and a downwardly extending hollow shaft 49 which is secured to the cutting-bolt plate 11, extends with sliding fit into each bearing bushing 48. The felt ring 47 is preferably provided with an inside diameter which is larger than the external diameter of the bushing 48 whereby the bushing 48 is loosely received therein.

The hollow shafts 49 enclose the shafts 41 which have a reduced diameter at this position, with sufiicient play to enable them to be eccentrically displaced relative to the shafts 41, by the extent a. The eccentricity required for relieving the cutting edges 9 is adjusted by lateral .angular adjusting members 50 embedded in the gear wheels 41, the upper angular portions of the adjusting members 50 enclosing the bushings 48 with exact fit. This structure thus constitutes a guide means for the cutting bolts 10.

The adjusting members 50 are radially adjustable to the required eccentricity a by means of screws 51 .against the pressure of cup springs 52. It is of importance that the eccentricities of both eccentric bushings 48 extend in exactly the same direction. In order to enable precision adjustment of the eccentricities, the top part is provided with clearances or recesses 53, preferably on the same side, so that both eccentric bushings 48 may be adjusted.

Before initiating operation of the device as illustrated in FIGURE 6, the adjusting members 50 are initially laterally displaced with respect to the rotational axis of the hubs 44, this lateral displacement being accomplished by means of rotation of the screws 51, the adjusting members 50 being held in the desired position by means of the cup springs 52 biasing the adjusting members against the heads of the screw 51. This lateral adjustment of the adjusting members 50 causes a corresponding lateral displacement of the bushings 48 and of the hollow shafts 49 positioned therein. Since the shafts 49 are secured to the support plate 11, said plate 11 having the cutting bolts secured thereto is also laterally displaced, preferably by a distance a whereby the cutting edges 9 of the cutting bolts 10 are positioned substantially in sliding engagement with edge of the bores 8.

Consequently, when operation of the razor is initiated, drive pinion 43 will cause a simultaneous rotation of hubs 44 having the adjusting members 50 fixedly secured thereto. However, since the adjusting members 50 having the bushings 48 confined therein in a laterally displaced relationship with respect to the rotational axes of the hubs 44, rotation of the adjusting members 50 causes the bushings 48 to be moved in an orbital or eccentric path, which path has a circular configuration. The orbital or circular movement of the bearings 48 thus causes a similar orbital movement of the support plate 11 and of the cutting bolts 10, whereby the cutting edges slide around the periphery of the bores 8 to perform a cutting function.

The construction illustrated in FIGURE 7 corresponds substantially to that illustrated in FIGURE 6. 'Its main distinguishing feature consists in the cutting-bolt plate 11 being driven by only one eccentric bushing 48, and in providing a guide means comprising three relief rollers for the tangential relief of the cutting edges 9, similar to the construction illustrated in FIGURES 1 to 5, as hereinafter described.

The drive mechanism illustrated in FIGURE 7 is substantially identical to the drive mechanism as illustrated in FIGURE 6 with the exception that the bushing 48 is positioned within an opening 65 provided in the adjusting member 50, which opening 65 is larger than the external diameter of the bushing 48 so as to permit relative lateral movement therebetween. On the other hand, in the embodiment illustrated in FIGURE 6, the bushing 48 was tightly confined with respect to the adjusting member 50 so that no relative lateral movement could occur therebetween. Since such lateral movement can occur in the embodiment illustrated in FIGURE 7 between the bushing 48 and the adjusting member 50, it is preferable to provide relief rollers as described below for controlling and limiting the orbital motion of the support plate 11.

Rigidly inserted in the top part 1 of the housing at positions close to the outer edge of the cutting plate 7 are three bearing shafts 54 which, like the single gear shaft 41, are mounted with their upper ends in the cutting plate 7 with exact fit, and, with rollers 55 interposed, pass through additional bores 56 provided in the cutting-bolt plate 11. The selected diameter of the bores 56 is such as to ensure that they have the same freedom of movement as that available in the bores 8, that is, the difference in diameter between the bore 56 and the relief roller 55 is substantially equal to the difference in diameter between the bore 8 and the cutting edge 9.

In the above-described embodiment, lateral displacement of the adjusting member 50 by means of the screw 51 causes the bushing 48 to be laterally displaced with respect to the rotational axis of the hub 44. This lateral displacement of the bushing 48 also causes a corresponding lateral displacement of the support plate 11, this lateral displacement being of a suflicient magnitude a so as to cause the sidewall of the bore 56 to contact the relief roller 55, thereby limiting the lateral displacement of the cutting edges 9. Rotation of the hub 44 and simultaneous rotation of the adjusting member 50 thus causes the bushing 48 and the support plate 11 to be moved with an orbital motion having a circular path, which motion causes the cutting edge 9 to slide around the periphery of the bores 8 to perform a cutting function. This orbital movement of the support plate 11 is limited by the rolling engagement of the relief rollers 56 with the periphery of the surrounding bores 55, which engagement also permits only a minimum contact pressure to exist between the cutting edges 9 and the surrounding bores 8 so as to prevent dulling or wearing of the cutting edges.

Although particular preferred embodiments of the invention have been disclosed above for illustrative purposes, it will be understood that variations or modifications thereof which lie within the scope of the appended claims are fully contemplated.

We claim:

1. In an electric razor head, comprising in combination:

an outer stationary cutting plate provided with a plurality of spaced cylindrical bores of substantially unifonm diameter throughout their axial lengths, a plurality of cutting bolts having bevelled heads forming cutting edges, said heads being eccentrically positioned within said cylindrical bores and being of smaller size than said bores so that a clearance is present therebetween, said heads being eccentrically rotatable within said cylindrical bores of the stationary cutting plate, an inner supporting plate connected to said cutting bolts, drive means connected to said inner supporting plate for effecting eccentric movement of the bevelled heads of the cutting bolts within said cylindrical bores, and adjustment means for adjusting the level of the cutting bolts relative to the level of the cutting plate.

2. A razor head according to claim 1, wherein said adjustment means includes rotatable means for effecting said adjustment.

3. A razor head according to claim 1, in which the razor head has a housing .and the cutting plate is positioned adjacent the top part of the housing, wherein the adjustment means comprises a rotatable ring having a plurality of depressions and being disposed between said outer stationary cutting plate and the top edge of the top part of the housing, said top part being provided with a plurality of cavities corresponding to and arranged for receiving said depressions.

4. A razor head according to claim 1, including guide means connected to said inner supporting plate and engaged with said cutting plate to limit the relative eccentric movement between said cutting plate and said heads.

5. A razor head according to claim 4, in which said guide means includes pins secured to the inner supporting plate and having rollers rotatably mounted thereon, and cylindrical bores in the cutting plate into which said rollers are eccentrically received, said rollers having substantially the same clearance in said bores as said cutting heads have in said clearance cutting head bores.

6. A razor head according to claim 1, including a frame member;

rigid, adjustable ball bearing means between said frame member and said supporting plate; and

resiliently biased ball bearing means between said supporting plate and said frame member for yieldably maintaining said supporting plate in a desired position relative to said cutting plate.

7. A razor head according to claim 1, in which the drive means includes an eccentric member which is movable in an orbital path, said eccentric member being connected to said supporting plate for similarly moving same, and further including a plurality of bearing shafts interconnected to said cutting plate, each of said bearing shafts having a roller thereon in engagement with said supporting plate for controlling the eccentric movement thereof.

8. A razor head according to claim 7, in which the drive means further includes adjusting means for adjusting the eccentricity of said eccentric.

9. A razor head according to claim 1, including guide means limiting the eccentric motion of said cutting heads for minimizing the contact pressure between said cutting heads and said bores, thereby preventing said cutting heads from quickly wearing and becoming dull.

References Cited UNITED STATES PATENTS Schick 3043.2 Wills 30-41.9 Testi 3043.2 Testi 3043.2 Wright 3043.2 X Berg 3043.2 X Dalkowitz 3043.2

MYRON C.

Grivetto 3043.2 Falcione 3043.2 X Bauerle 3041.9 Bauerle 3041.9 Messinger et a1 30-4392 Kleinman 3043.2 X Ammann 30-433.

FOREIGN PATENTS France. Great Britain.

KRUSE, Primary Examiner. 

